Browsing by Author "Xue, Dayuan"

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Comparative homegarden medical ethnobotany of Naxi healers and farmers in Northwestern Yunnan, China
(2014-01) Yang, Lixin; Ahmed, Selena; Stepp, John R.; Mi, Kai; Zhao, Yanqiang; Ma, Junzeng; Liang, Chen; Pei, Shengji; Huai, Huyin; Xu, Gang; Hamilton, Alan C.; Yang, Zhi-wei; Xue, Dayuan
Background Homegardens are ecologically and culturally important systems for cultivating medicinal plants for wellbeing by healers and farmers in Naxi communities of the Sino Himalayan region. The cultivation of medicinal plants in Naxi communities and associated ethnomedical knowledge base for maintaining and utilizing these resources is at risk with expanded commercialization of natural resources, development policies and rapid socio-economic change in China. Research is needed to understand the medicinal plant species maintained in Naxi homegardens, their use and contribution to community wellbeing, and how these practices and knowledge base varies between Naxi healers and farmers in order to develop plans for biodiversity conservation and preservation of ethnomedical practices. The main objective of this study is to document and compare medicinal plant species in Naxi homegardens and associated ethnomedical knowledge between Naxi healers and farmers. Methods Ethnobotanical homegarden surveys were conducted with three Naxi healers and 28 farmer households in two Naxi communities in Lijiang Prefecture in Northwest Yunnan Province of China. Surveys included inventories of medicinal plants in homegardens and semi-structured interviews with homegarden managers to document traditional medicinal uses of inventoried plants. Inventoried plants were classified into 13 ‘usage categories’ of medical condition groupings that impact a system of the body. Finally, plant species richness was calculated for each homegarden and species richness was compared between healers and farmers as well as between study sites using a Least Square Means Tukey HSD function. Results Ethnobotanical surveys at the study sites found that 13% of households rely exclusively on traditional Naxi medicine, 26% exclusively use Western medicine and 61% use a combination of traditional Naxi and Western medicine. A total of 106 medicinal plants were inventoried in Naxi homegardens representing 50 botanical families. Over 85% of inventoried medicinal plants were herbaceous. The most represented families were Asteraceae (12.8%), Ranunculaceae (8.3%), Apiaceae (8.3%), and Polygonaceae (7.3%). The primary medical functions of inventoried plants were to treat inflammation (73 species), circulatory system disorders (62), nervous system disorders (41), detoxification (39), digestive system disorders (33), muscular-skeletal system disorders (26), genitourinary system disorders (26), skin conditions (23), respiratory systems disorders (22), and cold and flu (20). Local herbal experts maintained greater medicinal plant species richness in their homegardens compared to local farmers as well as had greater knowledge of medicinal functions of plants. Healers maintained medicinal plants primarily for healing while farmer households maintained approximately 90% of the medicinal plants in their homegardens for commercialization and the remaining for household healthcare. Conclusions This study highlights the importance of biodiversity and traditional ecological and medical knowledge for human wellbeing and livelihoods in Naxi communities. Conservation efforts and policies are necessary to preserve the ecological and cultural base that maintains medicinal plant use by both healers and farmers in Naxi homegardens of the Sino Himalayan region.
Cultural and Ecosystem Services of Flowering Quince (Chaenomeles speciosa) in the Naxi and Tibetan Highlands of NW Yunnan, China.
(2015-09) Yang, Lixin; Ahmed, Selena; Stepp, John R.; Zhao, Yanqinag; Zeng, Ma Jun; Pei, Shengji; Xue, Dayuan; Xu, Gang
Naxi, Tibetan, Bai, Yi, and Han communities in the Hengduan Mountain region of China’s western Yunnan have an extensive history of cultivating flowering quince (Chaenomeles speciosa [Sweet] Nakai; Rosaceae; Fig. 1). Flowering quince is cultivated and utilized by communities for food, medicine, and as a windbreak barrier and soil protector at the edges of their fields and gardens (Gao et al. 2011). The Hengduan Mountains are characterized by limited fertile land and cultivated fields that have relatively low productivity. Socio–linguistic groups living in the area for hundreds of years have developed ecological knowledge regarding suitable plants to cultivate in order to support community wellbeing in this extreme habitat. This study presents an ethnobotanical profile of flowering quince and seeks to understand the cultural and ecosystem services it provides to communities in the Hengduan Mountain region. The main objective of this study is to understand the rationale for its traditional cultivation and to explore the potential commercial value of flowering quince.
Effects of Extreme Climate Events on Tea (Camellia sinensis) Functional Quality Validate Indigenous Farmer Knowledge and Sensory Preferences in Tropical China
(2014-10) Ahmed, Selena; Stepp, John Richard; Orians, Colin M.; Griffin, Timothy S.; Matyas, Corene; Robbat, Albert Jr.; Cash, Sean; Xue, Dayuan; Long, Chunlin; Unachukwu, Uchenna J.; Buckley, Sarabeth; Small, David; Kennelly, Edward
Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world's most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in a major tea producing area of China during an extreme drought through the onset of the East Asian Monsoon in order to capture effects of extreme climate events that are likely to become more frequent with climate change. Compared to the spring drought, tea growth during the monsoon period was up to 50% higher. Concurrently, concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower during the monsoon while total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in concentrations of tea secondary metabolites was accompanied by reduced farmer preference on the basis of sensory characteristics as well as a decline of up to 50% in household income from tea sales. Farmer surveys indicate a high degree of agreement regarding climate patterns and the effects of precipitation on tea yields and quality. Extrapolating findings from this seasonal study to long-term climate scenario projections suggests that farmers and consumers face variable implications with forecasted precipitation scenarios and calls for research on management practices to facilitate climate adaptation for sustainable crop production.
Plant-Climate Interaction Effects: Changes in the Relative Distribution and Concentration of the Volatile Tea Leaf Metabolome in 2014–2016
(2019-11) Kfoury, Nicole; Scott, Eric R.; Orians, Colin M.; Ahmed, Selena; Cash, Sean B.; Griffin, Timothy; Matyas, Corene; Stepp, John Richard; Han, Wenyan Han; Xue, Dayuan; Long, Chunlin; Robbat Jr., Albert
Climatic conditions affect the chemical composition of edible crops, which can impact flavor, nutrition and overall consumer preferences. To understand these effects, we sampled tea (Camellia sinensis (L.) Kuntze) grown in different environmental conditions. Using a target/nontarget data analysis approach, we detected 564 metabolites from tea grown at two elevations in spring and summer over 3 years in two major tea-producing areas of China. Principal component analysis and partial least squares-discriminant analysis show seasonal, elevational, and yearly differences in tea from Yunnan and Fujian provinces. Independent of location, higher concentrations of compounds with aromas characteristic of farmers’ perceptions of high-quality tea were found in spring and high elevation teas. Yunnan teas were distinct from Fujian teas, but the effects of elevation and season were different for the two locations. Elevation was the largest source of metabolite variation in Yunnan yet had no effect in Fujian. In contrast seasonal differences were strong in both locations. Importantly, the year-to-year variation in chemistry at both locations emphasizes the importance of doing multi-year studies, and further highlights the challenge farmers face when trying to produce teas with specific flavor/health (metabolite) profiles.
The Role of Montane Forests for Indigenous Dongba Papermaking in the Naxi Highlands of Northwest Yunnan, China. Mountain Research and Development.
(2011-11) Yang, Lixin; Stepp, John R.; Ahmed, Selena; Pei, Shengji; Xue, Dayuan
China's rapid economic development is influencing cultural practices and natural resource management in indigenous mountain communities throughout the country. Numerous studies have documented loss and change of cultural practices and environmental degradation in indigenous communities with the expansion of roads, markets, tourism, and other infrastructure development. The present study focuses on papermaking, a socioecological practice that began in China, as a case study to examine the influence of development on cultural practices and natural resource management. The Naxi are an indigenous people who primarily inhabit the mountains of the eastern Himalaya in China's northwest Yunnan province. The Naxi people are unique in that they have the last remaining pictographic writing system in the world. The Naxi pictographic script is customarily learned and mastered by shaman priests known as Dongba (Dto'mba) who transmit their knowledge to their sons. Approximately 300,000 Naxi live in this area. The pictographic system is transmitted on paper sourced from montane forest resources, primarily Wisktroemia delavayi. This cultural tradition almost disappeared during the Cultural Revolution in China during the 1960s and 1970s but has recently seen a revival. Research involved both ethnographic interviews and ecological sampling. Semistructured interviews were conducted with 100 informants between 2002–2011 to understand the management and use of W. delavayi for Dongba papermaking and the impact of market integration on papermaking. Sample plots were surveyed for floristic composition and structure in the 3 vegetation types where W. delavayi grows. Density, height, diameter, and number of branches of W. delavayiplants were recorded within each plot. Ecological importance values were calculated based on relative density, relative dominance, and relative frequency to determine the habitat where W. delavayidemonstrates the greatest growth. Additional plots were surveyed to understand the regeneration of W. delavayi after the local harvest cycle.
Striking changes in tea metabolites due to elevational effects
(2018-10) Kfoury, Nicole; Morimoto, Joshua; Kern, Amanda; Scott, Eric R.; Orians, Colin M.; Ahmed, Selena; Griffin, Timothy S.; Cash, Sean B.; Stepp, John R.; Xue, Dayuan; Long, Chunlin; Robbat, Albert Jr.
Climate effects on crop quality at the molecular level are not well-understood. Gas and liquid chromatography–mass spectrometry were used to measure changes of hundreds of compounds in tea at different elevations in Yunnan Province, China. Some increased in concentration while others decreased by 100’s of percent. Orthogonal projection to latent structures-discriminant analysis revealed compounds exhibiting analgesic, antianxiety, antibacterial, anticancer, antidepressant, antifungal, anti-inflammatory, antioxidant, anti-stress, and cardioprotective properties statistically (p = 0.003) differentiated high from low elevation tea. Also, sweet, floral, honey-like notes were higher in concentration in the former while the latter displayed grassy, hay-like aroma. In addition, multivariate analysis of variance showed low elevation tea had statistically (p = 0.0062) higher concentrations of caffeine, epicatechin gallate, gallocatechin, and catechin; all bitter compounds. Although volatiles represent a small fraction of the total mass, this is the first comprehensive report illustrating how normal variations in temperature, 5 °C, due to elevational effects impact tea quality.